PDF Viewer Update: Add metrics for thumbnail navigation

Bug: 652400
Change-Id: I7a08f0d58d5ca462fa5fe1a8dc4c06f0e8277151
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2402125
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806362}

chrome/browser/resources/pdf/metrics.js

@@ -181,7 +181,11 @@ PDFMetrics.UserAction = {
   ZOOM_CUSTOM_FIRST: 43,
   ZOOM_CUSTOM: 44,
 
-  NUMBER_OF_ACTIONS: 45,
+  // Recorded when a thumbnail is used for navigation.
+  THUMBNAIL_NAVIGATE_FIRST: 45,
+  THUMBNAIL_NAVIGATE: 46,
+
+  NUMBER_OF_ACTIONS: 47,
 };
 
 // Map from UserAction to the 'FIRST' action. These metrics are recorded
@@ -276,4 +280,8 @@ PDFMetrics.firstMap_ = new Map([
     PDFMetrics.UserAction.ZOOM_CUSTOM,
     PDFMetrics.UserAction.ZOOM_CUSTOM_FIRST,
   ],
+  [
+    PDFMetrics.UserAction.THUMBNAIL_NAVIGATE,
+    PDFMetrics.UserAction.THUMBNAIL_NAVIGATE_FIRST,
+  ],
 ]);

chrome/browser/resources/pdf/pdf_viewer.js

@@ -865,8 +865,9 @@ export class PDFViewerElement extends PDFViewerBaseElement {
       PDFMetrics.record(PDFMetrics.UserAction.FOLLOW_BOOKMARK);
     } else if (e.detail.origin === 'pageselector') {
       PDFMetrics.record(PDFMetrics.UserAction.PAGE_SELECTOR_NAVIGATE);
+    } else if (e.detail.origin === 'thumbnail') {
+      PDFMetrics.record(PDFMetrics.UserAction.THUMBNAIL_NAVIGATE);
     }
-    // TODO(dhoss): Add metrics for thumbnails.
   }
 
   /**

chrome/test/data/pdf/metrics_test.js

@@ -177,5 +177,24 @@ chrome.test.runTests(function() {
           chrome.metricsPrivate.actionCounter);
       chrome.test.succeed();
     },
+
+    function testMetricsThumbnail() {
+      PDFMetrics.resetForTesting();
+
+      chrome.metricsPrivate = new MockMetricsPrivate();
+      PDFMetrics.record(PDFMetrics.UserAction.DOCUMENT_OPENED);
+
+      PDFMetrics.record(PDFMetrics.UserAction.THUMBNAIL_NAVIGATE);
+      PDFMetrics.record(PDFMetrics.UserAction.THUMBNAIL_NAVIGATE);
+
+      chrome.test.assertEq(
+          {
+            [PDFMetrics.UserAction.DOCUMENT_OPENED]: 1,
+            [PDFMetrics.UserAction.THUMBNAIL_NAVIGATE_FIRST]: 1,
+            [PDFMetrics.UserAction.THUMBNAIL_NAVIGATE]: 2
+          },
+          chrome.metricsPrivate.actionCounter);
+      chrome.test.succeed();
+    },
   ];
 }());

tools/metrics/histograms/enums.xml

@@ -9766,6 +9766,8 @@ histogram as enum -->
   <int value="42" label="ZoomOut"/>
   <int value="43" label="ZoomCustomFirst"/>
   <int value="44" label="ZoomCustom"/>
+  <int value="45" label="ThumbnailNavigateFirst"/>
+  <int value="46" label="ThumbnailNavigate"/>
 </enum>
 
 <enum name="ChromePDFViewerAnnotationType">